The visible light generated by LEDs has certain advantages compared to visible light generated from other sources. Such advantages include high information security, a high signal noise ratio, none-interference from electronic magnetic frequencies, and being free of frequency allocation. Consequently, LEDs can be effectively utilized in fields of visible light communication and illumination.
Moreover, the high modulation speed of high-brightness LEDs has a bandwidth around 1 MHz. Therefore, the high-brightness LEDs may be utilized within visible light networks. Furthermore, RGB LEDs, or the combination of blue LEDs and phosphor are a few ways of attaining high-brightness LEDs.
However, due to phosphor's limited relaxation time, the modulation speed is limited to 1 MHz and the maximum data rate is 1 Mb/s. Additionally, the combination of blue LEDs and phosphor may not be implemented within indoor visible light signal transmissions.